JP3459729B2 - toner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in recording methods using electrophotography, electrostatic recording, magnetic recording and the like. More specifically, the present invention relates to a toner used in a copying machine, a printer or a fax machine, which forms a toner image on an electrostatic latent image carrier in advance and transfers the toner image onto a transfer material to form an image.

[0002]

2. Description of the Related Art Conventionally, a large number of electrophotographic methods are known, but generally, a photoconductive substance is used to form an electric latent image on a photoconductor by various means, and then,
The latent image is developed with toner to make it a visible image, and if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat / pressure to obtain a final image. It is a thing.

In recent years, there is an increasing demand for colorization of copying machines, printers and fax machines using electrophotography. Generally, it is difficult to use a magnetic toner containing a magnetic material as a color toner due to its tint, so a non-magnetic toner is used. When a magnetic toner is used as the black toner and a non-magnetic toner is used as the color toner, the optimum transfer current value of the non-magnetic toner tends to be higher than the optimum transfer current value of the magnetic toner. When the transfer conditions of the device body are adjusted to non-magnetic toner, the magnetic toner causes a phenomenon called "retransfer" in which the toner once transferred onto the transfer material returns to the latent image carrier, resulting in a black image. Causes a decrease in concentration.

Further, as paper materials have been further diversified in recent years, it is required that electrophotographic copying machines, printers, and fax machines be compatible with these various paper materials. However, the optimum transfer conditions differ depending on the paper material that is the transfer material. For example, for thick paper or OHT film, the optimum transfer current value is high. On the other hand, for thin paper, the optimum transfer current value is low, and if the transfer conditions of the device body are optimized for thick paper or OHT film, the “retransfer” phenomenon still occurs.

Japanese Unexamined Patent Publication (Kokai) No. 2-66559 and Japanese Unexamined Patent Publication (Kokai) No. 2-
No. 87159, JP-A-2-146557, JP-A-2-167566, JP-A-5-61251 and the like have been proposed that the transfer rate can be improved by subjecting the toner to mechanical shock treatment. There is.

In the methods proposed by these, the transfer rate is certainly improved when the transfer conditions are optimized for the toner, but the transfer efficiency when the transfer current value is set higher than that. Is hardly improved and has no effect on the improvement of "retransfer".

Further, as the colorization / high definition of the printer is advanced, the demand for higher quality of graphic images is higher than ever. In this situation,
The so-called "sleeve ghost", in which the afterimage of the previous image appears in the halftone portion in the cycle of the toner carrier, or when the uniform solid image is printed, the image densities of the first and second laps of the toner carrier are different. In some cases, development causes a problem in image quality.

Japanese Patent Laid-Open No. 2-284152 discloses a so-called "positive ghost" in which the previous image appears darker in the halftone portion and the image density after the second round of the toner carrier becomes higher than that at the first round. , The improvement is described.

However, with respect to the so-called "negative ghost", which is the opposite development to that described above, such that the halftone portion appears lighter and the image density on the first round of the toner carrier becomes higher than that on the second and subsequent rounds, Almost no reports have been made in the past.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner which solves the above problems of the prior art.

That is, an object of the present invention is to provide a toner capable of obtaining a high image density without causing "retransfer" under a wide range of transfer current conditions (especially under a high transfer current condition).

Another object of the present invention is to provide a toner capable of obtaining a good image without "sleeve ghost".

A further object of the present invention is to provide a toner having a high image density and capable of obtaining an image of good quality.

[0014]

Means for Solving the Problems] A toner having a particulate compound having toner particles and plate-like shape, the
The toner particles melt-knead the binder resin and other composition.
Process, crushing the kneaded product, and
Through the process of applying mechanical impact force to the crushed material
The toner is manufactured, and has one or more endothermic peaks in differential thermal analysis at 120 ° C. or less, and the shape factor SF1 of toner particles measured by an image analyzer is 11
0 <SF1 ≦ 180, and the value of the shape factor SF2 is 11
0 <SF2 ≦ 140, and the ratio B of the value B obtained by subtracting 100 from the value of SF2 and the value A obtained by subtracting 100 from the value of SF1
/ A is 1.0 or less, and the compound having a plate-like shape
Is the thickness in the direction perpendicular to the plate surface with respect to the longest diameter of the plate surface.
Is less than or equal to ¼ and is based on 100 parts by weight of toner particles.
It can solve the above problems by using a toner which is characterized that you have been added 0.01 to 1.0 parts by weight.

The inventors of the present invention have studied for the purpose of solving the "retransfer" and the "sleeve ghost", and have an endothermic peak in a differential thermal analysis in a relatively low specific range, and In a toner in which the toner particles have a specific shape with relatively few irregularities and plate-shaped fine particles are externally added to the toner mother particles, while satisfying the prevention of "retransfer", "sleeve ghost" I found that I can solve it.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The toner of the present invention has one or more endothermic peaks in differential thermal analysis at 120 ° C. or lower (more preferably 110 ° C. or lower).

Endothermic peak in differential thermal analysis is 120 ° C.
If it is not below, the effect of preventing "retransfer" cannot be sufficiently obtained.

Endothermic peak in differential thermal analysis is 120 ° C.
The toners below have a specific state in which the dispersion state of the magnetic material / charge control agent, etc. in the binder resin is different from the toner having no endothermic peak at 120 ° C. or less in the melt-kneading step in the production thereof. Presumed to be.

Endothermic peak in differential thermal analysis is 120 ° C.
It is effective if at least one of the following is present, and the endothermic peak may be at a position exceeding 120 ° C.
However, it is preferable that the endothermic peak in the differential thermal analysis does not exist below 60 ° C (preferably below 70 ° C). When the endothermic peak in the differential thermal analysis is below 60 ° C., the image density tends to be low. In addition, storage stability tends to be unstable.

The endothermic peak in the differential thermal analysis is 120 ° C.
As a means to have the form described below, a method of internally adding a compound having an endothermic peak in differential thermal analysis at 120 ° C. or lower is preferable.

The endothermic peak in the differential thermal analysis is 120 ° C.
Examples of the substance having one or more of the following include resins and waxes.

Examples of the resin include crystalline polyester resin and silicone resin.

As the wax, paraffin wax,
Petroleum wax and its derivatives such as microcrystalline wax and petrolactam, montan wax and its derivatives, hydrocarbon wax and its derivatives by the Fischer-Tropsch method, polyolefin wax represented by polyethylene and its derivatives, carnauba wax,
Natural waxes such as candelilla wax and their derivatives, and the like include oxides, block copolymers with vinyl monomers, and graft modified products. Alcohols such as higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid or compounds thereof; acid amides, esters, ketones, hydrogenated castor oil and its derivatives, vegetable waxes, animal waxes, etc.
Any material having a temperature of not higher than 0 ° C can be used.

Among these, it is particularly preferable in the toner of the present invention that the toner contains a polyolefin wax, a hydrocarbon wax by the Fischer-Tropsch method, a petroleum wax, or a higher alcohol.

Further, among the above, it is more preferable in the toner of the present invention that the toner contains a polyolefin wax, a hydrocarbon wax by the Fischer-Tropsch method, or a petroleum wax.

It is considered that these compounds have relatively low polarities and stabilize the charging of the toner base. It is believed that this facilitates the "retransfer" prevention effect of the present invention.

Among these, polyolefin or hydrocarbon wax by the Fischer-Tropsch method, petroleum wax or higher alcohol is
When the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) in the GPC measurement is 1.0 to 2.0, the “retransfer” prevention effect is further enhanced.
By including the resharp wax having a (Mw / Mn) of 1.0 to 2.0 and a sharp molecular weight distribution in the toner, the magnetic substance in the binder resin and the charge control in the melt-kneading step in the production of the toner are controlled. It is considered that the state of dispersion of the agent and the like becomes a more preferable state for the present invention.

Further, the toner of the present invention has a shape factor SF1 of 110 <S measured by an image analyzer of toner particles.
F1 ≦ 180 (more preferably 120 <SF1 ≦ 1
60), the value of the shape factor SF2 is 110 <SF2 ≦ 140.
(More preferably 115 <SF2 ≦ 140), SF
The value of 2 minus 100 minus the value of SF1 and 100 from SF1
When the ratio B / A with the value A obtained by subtracting 1.0 is 1.0 or less, it is effective in preventing "retransfer".

When SF1 is 110 or less, and S
If F2 is 110 or less, or if the ratio B / A exceeds 1.0, it becomes difficult to clean the transfer residual toner remaining on the latent image carrier, and cleaning failure easily occurs.

When SF1 exceeds 180, and SF
When 2 exceeds 140, further improvement of the "retransfer" preventing effect cannot be obtained sufficiently.

The following method can be used to control the shape of the toner of the present invention within the above range.

Examples of the method include fine pulverization using a mechanical impact type fine pulverization device and jet pulverization in which the pulverization pressure is lowered than usual to increase the number of circulations and fine pulverization. Further, a hot water bath method in which finely pulverized or further classified toner particles are dispersed and heated in water, a heat treatment method in which a hot air stream is passed, a mechanical impact method in which mechanical energy is applied, and the like are included. .

In the present invention, among these methods, the method of applying treatment by mechanical impact force is adopted . Examples of the process for applying a mechanical impact force include, for example, a method of applying a mechanical impact force to a toner by a mechanical impact type crusher such as a Kawasaki Heavy Industries, Ltd.'s Kryptron system or a turbo industry's turbo mill, and Hosokawa Micron Corporation. Like the Mechano-Fusion System manufactured by Nara Machinery Co., Ltd. and the hybridization system manufactured by Nara Machinery Co., Ltd., the toner is pressed against the inside of the casing by centrifugal force with the blades that rotate at high speed, and the toner is mechanically pressed by the force such as compression force and friction force. There is a method of applying a dynamic impact force.

When the process of applying the mechanical impact force is performed after the finely pulverizing step of the toner or after the further classifying step, the effect of preventing "retransfer" is further enhanced. However,
When the shape of the toner particles is a shape having relatively few irregularities as in the present invention, the toner is likely to be clogged, and the “tap density”, which is the bulk density when the toner is given a certain vibration, becomes large. It turns out that there is a tendency.

Further, according to our study, the toner having a high tap density is supplied to the sleeve more than necessary due to the idle rotation of the sleeve before the development, and the density is higher in the first round of the sleeve than in the second round and thereafter. It was found that a so-called negative ghost, which becomes darker, is likely to occur.

Therefore, the toner tap density was examined, and it was found that the tab density of the toner was moderately reduced by externally adding plate-like fine particles to the toner mother particles, and the toner was used more than necessary on the first circumference of the sleeve. By preventing the toner from being taken in, "negative ghost" could be prevented.

If the fine particles are not plate-shaped, the tap density cannot be suppressed to an appropriately low level, and there is no effect in preventing "negative ghost".

The term "plate-like" as used herein means that the thickness in the direction perpendicular to the plate-like surface is 1/4 or less of the longest diameter of the plate-like surface.

In the present invention, the longest diameter and thickness of the plate-like surface of the plate-like fine particles are obtained from the average value of 100 or more particles measured by an electron micrograph at a magnification of 10,000 times.

When viewed from the side (thickness side), the plate-like fine particles appear as a very elongated rectangle as compared with the case where the plate-like surface is viewed. Therefore, the longest diameter is the electron micrograph.
Particles with apparent plate-like surfaces were sampled and measured, and thickness was measured by sampling particles with clearly visible side surfaces.

The average particle diameter of the plate-like fine particles is 1.0
The thickness is preferably 1 μm to 15.0 μm. If the average particle size of the plate-shaped fine particles is less than 1.0 μm, the tap density is not sufficiently reduced, and there is no effect in preventing “negative ghost”. When the average particle diameter of the plate-like fine particles exceeds 15.0 μm, the tap density becomes too small, the toner cannot be sufficiently supplied to the sleeve, and the density becomes too thin.

In the present invention, the average particle size of the plate-like fine particles means the average value of the longest diameters of the plate-like particles of the plate-like fine particles.

Further, the fine particles are used in a form externally added to the toner base. In the state where the fine particles are internally added to the base of the toner, there is no effect of keeping the tap density small,
It is not effective in preventing "negative ghosts".

The amount of the fine particles added to the toner base is 0.01 to 1.0 with respect to 100 parts by weight of the toner base.
Ru parts by weight of Der. The amount of fine particles added to the toner is 0.01
If it is less than the mass part, the effect of suppressing the tap density is not sufficient, and the effect of preventing "negative ghost" cannot be sufficiently obtained. When the amount of the fine particles added to the toner exceeds 1.0 part by mass, the tap density becomes too small and a good density cannot be obtained.

The plate-like fine particles include layered aluminosilicate compounds such as talc, kaolinite and mica and calcite, as well as plate-like metal sulfides such as iron sulfide and molybdenum sulfide,
Examples include plate-shaped boron nitride, plate-shaped graphite, plate-shaped organic resin particles, and the like.

Among these, plate-like boron nitride is preferable because of its high effect of preventing "sleeve ghost".

Further, these fine particles may be subjected to a hydrophobic treatment or the like, if necessary.

When the plate-like fine particles of the present invention are externally added to the conventional toner particles having a relatively large number of irregularities that exceed the range of the shape of the toner particles of the present invention, the tap density becomes smaller than an appropriate value. , Is not effective in preventing "sleeve ghost".

Examples of the binder resin that can be used in the present invention include the following. In the case of a heat fixing toner, for example, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene, or a substitution product thereof; a styrene-vinylnaphthalene copolymer, a styrene-acrylic acid ester copolymer, Styrene-methacrylic acid ester copolymer, styrene-maleic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-maleic acid copolymer, styrene-α-chloromethyl methacrylate Copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene type such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile indene copolymer Copolymer; polyvinyl chloride,
Phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, tempen resin , Coumarone indene resin, petroleum resin, etc. can be used.

Among these, the styrene-based copolymer is
The effect of preventing "retransfer" is further enhanced, which is particularly preferable.

It is considered that the resin obtained by the radical polymerization reaction has a relatively low main-chain polarity and stabilizes the charging of the toner base. It is believed that this facilitates the "retransfer" prevention effect of the present invention.

Examples of the comonomer for the styrene monomer of the styrene type copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate,
Didecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a heavy bond or a substituted product thereof; acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid and crotonic acid, and α- or β-alkyl derivatives thereof, fumaric acid, maleic acid, citraconic acid Unsaturated dicarboxylic acids and their monoester derivatives, maleic anhydride, etc. are available. Such monomers can be used alone or in admixture and copolymerized with other monomers to produce a desired polymer.

Among these, it is particularly preferable to use a monoester derivative of unsaturated dicarboxylic acid. More specifically, for example, monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monoallyl maleate, monophenyl maleate,
Α-, β such as monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monophenyl fumarate etc.
-Unsaturated dicarboxylic acid monoesters; alkenyldicarboxylic acids such as n-butenyl monosuccinate, n-octenyl monosuccinate, n-butenyl malonate monoethyl, n-dodecenyl glutarate monomethyl, n-butenyl adipate monobutyl and the like. Monoesters of aromatic dicarboxylic acids such as phthalic acid monomethyl ester, phthalic acid monoethyl ester, phthalic acid monobutyl ester, etc .; Vinyl such as vinyl chloride, vinyl acetate, vinyl benzoate, etc. Esters, for example, ethylene-based olefins such as ethylene, propylene, butylene, etc .; vinyl ketones, such as vinyl methyl ketone, vinyl hexyl ketone, etc .; for example, vinyl methyl ether, vinyl ethyl ether, vinyl iso Vinyl ethers such as Chirueteru; vinyl monomers are used alone or in combination.

As the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used. For example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; Carboxylic acid ester having two double bonds such as acrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone, and 3 or more. The compounds having a vinyl group can be used alone or as a mixture.

The toner of the present invention is particularly effective in the case of a magnetic toner containing a magnetic substance in the toner.

The magnetic substance contained in the toner of the present invention is preferably powder of an alloy or compound containing a ferromagnetic element. For example, magnetite, maghemite, ferrite, etc., alloys and compounds of iron, cobalt, nickel, manganese, zinc, etc., other ferromagnetic alloys, etc., which are conventionally known as magnetic materials can be mentioned.

The BET specific surface area of the magnetic powder by the nitrogen gas adsorption method is 1 to 40 m ² / g, further ^{2 to} 30 m ²
/ G is preferable.

The average particle size of the magnetic powder is 0.05 to 1
μm, preferably 0.1 to 0.6 μm.

Further, the magnetic substance is a binder resin 100 in the toner.
It is preferable to contain 60 parts by mass to 200 parts by mass, more preferably 80 parts by mass to 150 parts by mass with respect to parts by mass.

Further, the toner of the present invention is particularly preferable when it contains a magnetic material having a substantially spherical shape. Unlike the case where the state of dispersion of the magnetic substance in the binder resin in the melt-kneading step in the production is one in which the shape of the magnetic substance is other than substantially spherical, a certain specific surface state becomes a more preferable form, We believe that the effect of preventing "transfer" will be enhanced. When the shape of the magnetic material is “substantially spherical”, the average of the ratio of the major axis to the minor axis (major axis / minor axis) of each particle (100 or more is measured) is 1. 0 to 1.2 is used.

In the toner of the present invention, a charge control agent can be used by blending with toner particles (internal addition) or by mixing with toner particles (external addition), which is preferable. The charge control agent makes it possible to control the optimum charge amount according to the developing system, and particularly in the present invention, the balance between the particle size distribution and the charge amount can be further stabilized. Examples of substances that control the toner to be negatively charged include the following substances.

Organic metal complexes and chelate compounds are effective, for example, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid metal complexes. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

In the toner of the present invention, it is preferable that the inorganic fine powder is externally added to the developer.

The inorganic fine powder is preferably contained in the developer by stirring and mixing the developer with a mixer such as a Henschel mixer.

The inorganic fine powder used in the present invention includes:
Inorganic fine powder such as silicic acid fine powder, titanium oxide, and aluminum oxide is preferable, and silicic acid fine powder is particularly preferable. For example, as the silicic acid fine powder, both a so-called dry method produced by vapor phase oxidation of a silicon halide or a dry silica called fumed silica and a so-called wet silica produced from water glass or the like can be used. However, there are few silanol groups on the surface and inside the silica fine powder,
Further, dry silica having less production residue such as Na ₂ O and SO ₃ ²⁻ is preferable. Further, in the case of dry silica, in the manufacturing process, for example, aluminum chloride, titanium chloride, etc.
By using another metal halogen compound together with a silicon halogen compound, it is possible to obtain a composite fine powder of silica and another metal oxide, and it is also possible to include them.

It is also possible to use one whose surface has been previously made hydrophobic with an organic compound. Examples of such an organic treatment method include a method of treating with an organometallic compound such as a silane coupling agent or a titanium coupling agent which reacts or physically adsorbs with the inorganic fine powder; or after treatment with a silane coupling agent, or silane. A method of treating with a coupling agent and at the same time treating with an organic silicon compound such as silicone oil can be mentioned.

[0067] Inorganic fine powder used in the present invention the specific surface area according to the measured nitrogen adsorption 30 m ² / g or more by the BET method, particularly preferably in the range of 50 to 400 m ² / g.

The weight average particle diameter of the toner is 10.0 μm.
It is preferably m (preferably 8.0 μm) or less. When the weight average particle diameter of the toner is 10.0 μm or less, the effect of preventing “retransfer” is further enhanced. It is considered that when the weight average particle diameter of the toner is 10.0 μm or less, the charge amount of the toner on the electrostatic latent image carrier or the intermediate transfer body before transfer is further increased.

Further, as a method for producing the toner of the present invention, the following method can be mentioned. In the production of the toner according to the present invention, a mixing process using the above-mentioned constituent materials using a mixer such as a Henschel mixer, a ball mill, a V-type mixer, a heat roll kneader and an extruder is used. Kneading step, after cooling and solidifying the kneaded product, a crushing step using a crusher such as a jet mill,
It is preferably manufactured through a manufacturing process including at least the above process. Further, if necessary, it is also preferable to go through a classification step of the pulverized material.

Among these, a production method having at least a step of melt-kneading the binder resin and the other composition and a pulverization step of finely pulverizing the binder resin is particularly preferable in the production step.

In the melt-kneading step, when the endothermic peak in the differential thermal analysis is 120 ° C. or less, the dispersion state of the magnetic substance and the charge control agent in the binder resin becomes a preferable state for the present invention, and it should be crushed. As a result, the specific state is exposed as it is on the toner surface, and the effect of preventing "retransfer" is exhibited.

In the present invention, SF-indicating the shape factor
1 and SF-2 are, for example, Hitachi FE-SEM
(S-800) is used to randomly sample 100 toner images of 2 μm or more magnified 1000 times, and the image information is introduced into an image analysis device (LuzexIII) manufactured by Nicolet Co., Ltd. through an interface for analysis. And the values obtained by the calculation using the following equation are used as shape factors SF-1, S
It is defined as F-2.

[0073]

[Equation 1]

(Where MXLNG is the absolute maximum length of the particle,
PERIME represents the perimeter of the particle, and AREA represents the projected area of the particle. )

The shape factor SF-1 indicates the degree of roundness of the toner particles, and the shape factor SF-2 indicates the degree of unevenness of the toner particles.

The endothermic peak in the differential thermal analysis according to the present invention is measured by a highly accurate internal heat input compensation type differential scanning calorimeter. For example, DSC- manufactured by Perkin Elmer
7 can be used. The measuring method is ASTM D3418-
82. The DSC curve used in the present invention is
After raising the temperature once and taking the previous history, the temperature rate was 10 ° C / mi.
n, a DSC curve measured when the temperature is raised and lowered in the temperature range of 0 to 200 ° C is used. What is the endothermic peak temperature?
In the DSC curve, it is the peak temperature in the positive direction, that is, the point at which the differential value of the peak curve becomes 0 when the differential value changes from positive to negative.

The weight average particle diameter of the toner of the present invention is measured by using Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Co.). 1 electrolyte
Prepare a 1% aqueous NaCl solution using graded sodium chloride. For example, ISOTONR-II (manufactured by Coulter Scientific Japan) can be used. As the measuring method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 5 measuring samples are further added.
Add 20 mg. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and a 100 μm aperture is used as a rear aperture by the above measuring device to
The volume distribution and the number distribution of the toner having a size of μm or more were measured to calculate the volume distribution and the number distribution. Then, a weight-based weight average particle diameter D4 (the median value of each channel is set as a representative value for each channel) determined from the volume distribution according to the present invention was determined.

As the tap density measuring method of the present invention,
A value measured using a powder tester manufactured by Hosokawa Micron Co., Ltd. and a container attached to the powder tester according to the procedure in the instruction manual of the powder tester.

[0079]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention.

(Example 1) Styrene-butyl acrylate-butyl maleate-half ester copolymer 100 parts by weight Magnetite (shape: spherical, average particle size: 0.2 μm) 100 parts by weight Iron complex of monoazo dye (negative) Charge control agent) 2 parts by mass Low molecular weight polyethylene (differential thermal analysis endothermic peak: 102 ° C., Mw / Mn: 1.3) 4 parts by mass After premixing the above materials, a twin-screw kneading extruder set to 130 ° C. Melt kneading was carried out. After cooling the kneaded product, it was roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified by an air classifier. Further, the surface treatment was performed by a mechanical impact force to obtain a black powder toner base material A.

Hexamethyldisilazane / dimethylsilicone oil-treated dry silica: 1.2 parts by weight, plate-like boron nitride fine particles (average particle size: 6.0 μm, thickness: 100 parts by weight of the above black fine powder A) : 0.8 μm) 0.
3200 parts by mass with Henschel mixer 10B
A toner was obtained by stirring and mixing at pm for 2 minutes.

The weight average particle diameter of the obtained toner is 6.9 μm.
m, SF1 was 144, and SF2 was 126. Also,
The endothermic peak in the differential thermal analysis was at 102 ° C.

Observation of the toner surface with an electron microscope showed that the externally added boron nitride fine particles were adhered to the toner particle surface and were not embedded in the toner surface.

The types and physical properties of the external additives used in the examples are shown in Table 1 below, and the types and physical properties of the wax in the toner base and the particle size and shape of the toner base are shown in Table 2.

(Examples 2 to 3 and Reference Example ) A toner was obtained in the same manner as in Example 1 except that the boron nitride added in Example 1 was changed to the fine particles b to d shown in Table 1.

(Examples 4 to 6 ) Toners were obtained in the same manner as in Example 1 except that the amount of boron nitride added in Example 1 was changed to the amount shown in Table 3.

(Examples 7 to 13 ) Toner mothers B to H were obtained in the same manner as in Example 1 except that the substances shown in Table 2 were added instead of the low molecular weight polyethylene added in Example 1. A toner was obtained in the same manner as in Example 1 in the addition step.

(Examples 14 and 15 ) The toner bases I to I were prepared in the same manner as in Example 1 except that the shape shown in Table 2 was adjusted by adjusting the conditions of the mechanical shock treatment performed in Example 1. J was obtained, and a toner was obtained in the same manner as in Example 1 in the external addition process.

Comparative Example 1 Polyester resin (condensation polymer of propoxylated bisphenol and fumaric acid) 100 parts by mass Magnetite (shape: octahedron, average particle size: 0.2 μm) 60 parts by mass Iron complex of monoazo dye (negative) Charge control agent) 2 parts by mass Low molecular weight polypropylene (differential thermal analysis endothermic peak: 145 ° C., Mw / Mn: 8.8) 4 parts by mass Biaxial kneading extruder set to 130 ° C. after premixing the above materials Melt kneading was carried out. The kneaded product was cooled, coarsely pulverized, finely pulverized by a pulverizer using a jet stream, and further classified by an air classifier to obtain a black powder toner base K.

Hexamethyldisilazane / dimethylsilicone oil-treated dry silica: 1.2 parts by weight, tabular boron nitride fine particles (average particle size: 6.0 μm) per 100 parts by weight of the above black fine powder K: 0.3 parts by mass of the Henschel mixer 10B was stirred and mixed at 3200 rpm for 2 minutes to obtain a toner.

The weight average particle diameter of the obtained toner is 11.3.
μm, SF1 was 160, and SF2 was 154.

<Evaluation> The toners of the above Examples and Comparative Examples were evaluated by the following methods. The results are shown in Tables 3 and 4.

1) Evaluation of transferability Laser beam printer LBP-1260 manufactured by Canon Inc.
Was developed and a device equipped with a variable transfer bias power supply was used to develop a solid black image in an environment of 23 ° C / 60% RH,
Transfer the image onto a transfer paper of 75 g / m ² , transfer the residual image on the photoconductor with transparent polyester adhesive tape and stick it on a white paper. Measure the reflection density with a Macbeth reflection densitometer and use it as a standard. The value obtained by subtracting the density of the portion in which only the tape was attached to the white paper was evaluated. The transfer voltage was evaluated in steps of 0.5 kV from 1.0 to 3.0 kV. 2) Evaluation of Sleeve Ghost Apple Laser Beam Printer (6 / 600P
S) is used to take out the paper on which the solid black image is printed in an environment of 23 ° C./60% RH before passing through the fixing process. The amount of glue was measured and evaluated by the rate of increase (%) of the amount of glue in the second round portion with respect to the first round portion.

When the absolute value of the increase rate is 1.0 or less, the "sleeve ghost" is visually unnoticeable, and when the absolute value is 2.0 or less, it is hardly noticeable.

[0095]

[Table 1]

[0096]

[Table 2]

[0097]

[Table 3]

[0098]

[Table 4]

[0099]

According to the present invention, "retransfer" does not occur even under a high transfer current condition, and an image of good quality without sleeve ghost can be obtained.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI G03G 9/08 381 (72) Inventor Shigeo Urawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Yusa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP 63-235955 (JP, A) JP 63-235953 (JP, A) JP 61-279864 (JP, A) JP-A-8-184990 (JP, A) JP-A-8-15900 (JP, A) JP-A-7-306545 (JP, A) JP-A-7-248645 (JP, A) A) JP 7-209952 (JP, A) JP 7-152199 (JP, A) JP 7-72654 (JP, A) JP 6-250438 (JP, A) JP 6 -11884 (JP, A) JP-A-5-297629 (JP, A) JP-A-5-24973 5 (JP, A) JP 5-197192 (JP, A) JP 5-72801 (JP, A) JP 2-256065 (JP, A) JP 1-185654 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (15)

(57) [Claims] 1. A toner comprising toner particles and fine particles of a compound having a plate-like shape , wherein the toner particles melt-knead a binder resin and another composition.
And the step of crushing the kneaded product, and the crushing step,
The process of applying a mechanical impact force to the finely pulverized product
The toner has one or more endothermic peaks in differential thermal analysis at 120 ° C. or lower, and the shape factor SF1 of the toner particles measured by an image analyzer is 110 <SF1 ≦ 180. the value of the shape factor SF2 is the 110 <SF2 ≦ 140, Oh the ratio B / a of the value a obtained by subtracting 100 from the values of B and SF1 minus 100 from the value of SF2 is 1.0 or less
Therefore, the compound having a plate-like shape is
The thickness in the direction perpendicular to the plate-like surface is 1/4 or less,
-Addition of 0.01 to 1.0 parts by mass to 100 parts by mass of particles
Toner characterized by being added . 2. The average particle diameter of the fine particles is 1.0 to 15.0.
The toner according to claim 1, wherein the toner has a thickness of μm. 3. The toner according to claim 1, wherein the fine particles are boron nitride. 4. The toner according to claim 1, wherein the toner has one or more endothermic peaks in differential thermal analysis at 60 ° C. to 120 ° C. 5. The toner according to claim 4, wherein the toner has one or more endothermic peaks in differential thermal analysis at 70 ° C. or higher. 6. The toner according to claim 4, wherein the toner has one or more endothermic peaks in a differential thermal analysis at 110 ° C. or lower. 7. The toner according to claim 1, wherein the toner contains a polyolefin wax, a hydrocarbon wax by a Fischer-Tropsch method, a petroleum wax, or a higher alcohol. 8. The toner according to any one of claims 1 to 6, wherein the toner contains a polyolefin wax, a hydrocarbon wax by a Fischer-Tropsch method, or a petroleum wax. 9. The Mw / Mn measured by GPC of a polyolefin wax, a hydrocarbon wax, a petroleum wax, or a higher alcohol by the Fischer-Tropsch method contained in the toner is 1.0 to 2.0. The toner according to any one of claims 1 to 8. 10. The shape factor SF1 measured by an image analyzer of the toner particles is 120 <SF1 ≦ 160, the shape factor SF2 is 115 <SF2 ≦ 140, and 100 is subtracted from the value of SF2. 10. The toner according to claim 1, wherein a ratio B / A of the value B and the value A obtained by subtracting 100 from the value of SF1 is 1.0 or less. 11. A styrene-based copolymer is used as a binder resin for the toner.
The toner according to any one of 1. 12. The toner according to claim 1, wherein the toner contains a magnetic material. 13. The toner according to claim 12, wherein the magnetic substance in the toner is magnetic iron oxide having a substantially spherical shape. 14. The toner has a weight average particle diameter of 10.0 μm.
The toner according to any one of claims 1 to 13, wherein the toner is m or less. 15. The toner has a weight average particle diameter of 8.0 μm.
The toner according to any one of claims 1 to 13, wherein: